Rev is a small basic protein that is essential for HIV replication. This program outlines a comprehensive plan to answer important questions about the mechanism of Rev function, and to identify small molecule inhibitors of Rev-RRE interactions that provide the basis for developing anti-HIV therapeutics. Rev associates with a region in the viral mRNA termed the Rev Responsive Element to form an oligomeric complex that targets the mRNA for export from the nucleus, which constitutes a viable target for novel antiviral therapies. This program consists of six interrelated Projects and Core components that apply a variety of experimental approaches to study the RNA binding and nuclear export functions of Rev and to identify inhibitors of those functions. We will characterize the interactions of Rev with the RRE RNA using in vitro assays and develop screening methodologies for identification of Rev inhibitors. The disciplines that will be applied to understanding and targeting Rev include cell biology, biochemistry, structural biology, biophysics, and synthetic organic chemistry. Using this broad but well-integrated approach, we will address key remaining questions about the mechanism of Rev function, address the validity of Rev as a therapeutic target, and generate small molecule lead compounds that will stimulate drug discovery efforts involving this important but under-exploited HIV target.